The subject matter disclosed herein relates to recreational structures. More particularly, the subject matter disclosed herein relates to a spring arrangement and a spring configuration for a recreational structure, such as a trampoline.
FIG. 1 illustratively depicts the forces that are applied to a frame of a trampoline that has conventionally configured spring members. More specifically, FIG. 1 illustratively depicts a cross-sectional view of a frame 101 is part of, for example, a circular frame that forms the perimeter of a trampoline. Frame 101 is disposed on a vertical frame member 102, such as a leg of the trampoline. A spring member 103 mechanically connects a rebounding surface (not shown) to frame 101. In particular, a hook member 104 that is part of spring member 103 is inserted through a hole 105 (not plainly shown in FIG. 1) that is in the “top” of frame 101. Other spring members that are disposed behind spring member 103 and are not visible in FIG. 1 are mechanically connected to frame 101 in the same manner has shown in FIG. 1.
As the rebounding surface of the trampoline is jumped on, a horizontal force 106 and a vertical force 107 are applied to spring member 103 that is transmitted to frame 101. The nature of the mechanical connection of spring member 103 to frame 101, that is, the mechanical connection of hook member 104 through hole 105, causes a torque 108 to be applied to frame 101. Torque 108 causes vertical frame member 102 to bow outward from the center of the trampoline, as depicted by arrow 109.
The cyclic loading caused by torque 108 has a tendency to cause fatigue in vertical frame member 102 at the mechanical connection between frame 101 and vertical frame member 102 and along the length of vertical frame member 102.
What is needed is a technique for reducing the torque applied to a frame member of a trampoline, thereby minimizing the bowing and the fatigue caused in a vertical frame member of a trampoline.